1. Field of the Invention
This invention relates to a computer controlled, internal combustion engine designed to operate on a six-stroke cycle, wherein water is injected into each of the one or more cylinders during a predetermined portion of the six-stroke cycle depending upon the energy content within the cylinder subsequent to ignition of the conventional air-fuel mixture. The residual heat from the ignited air-fuel mixture serves to convert the injected water into steam on a controlled basis, thereby creating an auxiliary power stroke.
2. Description of the Related Art
It is well known that for over a hundred years the internal combustion (IC) engine was and is the dominating source of power for motorized vehicles. Other than rotary engines, the typical IC engine incorporates a plurality of piston and cylinder assemblies each of which includes a cylinder having a piston reciprocally mounted therein and wherein a combustible fluid, such as an air-fuel gaseous mixture, is forced into the interior of the cylinder, compressed and subsequently ignited. The ignition of the combustible fluid causes a significant expansion of gases within the cylinder, resulting in the piston being forced downwardly within the cylinder and thereby, defining what is commonly known as a xe2x80x9cpower strokexe2x80x9d. The piston is drivingly connected to a crank shaft which is drivingly connected to the remainder of the drive train associated with the motorized vehicle.
Over the years, numerous attempts have been made to increase the efficiency of IC engines, while at the same time protecting the environment by eliminating or significantly reducing the exhausting of pollutants into the surrounding atmosphere. Attempts to protect the environment, have resulted in significant improvements in exhaust systems, fuel compositions and other operational components of modern IC engines, which sometimes derogatorily affect the efficiency or performance characteristics of such engines. Other attempts to improve the performance of IC engines, without harming the environment, have the included the design of an IC engine which operates on a six-stroke cycle. In such designs, the first four strokes function as a conventional internal combustion engine and include an intake stroke, compression stroke, power stroke and exhaust stroke. The last two strokes of the six-stroke cycle include the injection of water into the combustion chamber for purposes of converting the water to steam by using the residual heat remaining therein. The expansion of the steam is intended to provide an additional power stroke, without additional fuel or combustible fluid being supplied. However, for the most part, such known attempts have failed to provide an internal combustion engine capable of operating on a six-stroke cycle, which is sufficiently efficient and effective for wide spread commercial use.
In order to understand the problems associated with the effective development of an IC engine of the type set forth above, it is important to understand the relationship between water, steam, temperature and pressure, all of which are governed by the laws of thermodynamics, and more specifically, by what are commonly referred to as the xe2x80x9cSteam Tablesxe2x80x9d. Accordingly, and based on these laws, it is well recognized that in a closed container or system, for example, heated water will be maintained in a liquid state at a temperature of 297 degrees Fahrenheit, only as long as the pressure is maintained at a minimum of 50 PSI. However, if the heated water were suddenly to be released from the closed container into atmosphere it would immediately xe2x80x9cflashxe2x80x9d into steam due to the significant drop in pressure. The reason for this instant conversion into steam is because the water has sufficient latent heat for the steam conversion and no longer has to absorb heat from an exterior source.
Prior attempts to take advantage of the force generated when the water converts to steam in the combustion chamber or cylinder an IC engine have, for the most part, failed due to the fact that the water was injected and allowed to convert or xe2x80x9cflashxe2x80x9d into steam at the wrong time during the six-stroke cycle. Allowing all of the water injected into a cylinder to simultaneously flash into steam would most probably result in damage to the engine due to the xe2x80x9cinstantxe2x80x9d expansion force created. Rather than developing a power stroke in the engine, such an expansive force would have a tendency to crack the engine block or cause a failure in the seals between the piston and the interior surface of the cylinder. Accordingly, it is believed by the inventor hereof that in order to develop an efficient IC engine incorporating the conversion of injected water into steam, the conversion should be controlled and take place continuously or gradually over the duration of a specific predetermined portion of the six-stroke cycle, rather than instantaneously upon injection of the water into the cylinder.
The failure of previous attempts at water to steam conversion is further evidenced by an explanation of the ignition of a conventional air-fuel mixture in a conventional IC engine. More specifically, after the air-fuel mixture is compressed and ignited, the mixture burns and expands, thereby supplying a continuous force which drives the piston the length of the cylinder resulting in a xe2x80x9cpower strokexe2x80x9d. This happens because the combustion of the air-fuel mixture occurs on a substantially continuous basis as the piston travels the length of the cylinder during the power stroke. All of the force or power resulting from the ignition of the air-fuel mixture is not released or exerted on the piston at one point in time. Therefore, it is believed by the inventor hereof that the control of the conversion of water into steam should similarly occur on a continuous rather than an instantaneous basis in order for such conversion to produce an effective and efficient additional power stroke in a six-stroke cycle.
Another characteristic common to known attempts to develop a six-stroke cycle IC engine is the premature exhausting of the conventional air-fuel mixture after it has been ignited. It is generally accepted that approximately 30% of the energy (heat) of the fuel charge is lost in the exhaust gases due to inherent designs of known or substantially conventional IC engines. However, if the exhaust gases can be maintained within the cylinder and properly mixed with a quantity of water being injected, the heat energy still remaining in the previously ignited fuel charge can be utilized to add another power stroke, occurring upon the conversion of water into steam within the cylinder.
Based on the above, there is a significant and recognized need for the development of an improved internal combustion engine which is capable of efficiently operating on a six-stroke cycle which includes the development of an additional power stroke through the injection of water into the cylinder or combustion chamber and the conversion of water into steam. The water to steam conversion should occur on a controlled basis and be at least partially dependent on the energy content within the cylinder, subsequent to ignition of a conventional air-fuel mixture and prior to the ignited air-fuel mixture being exhausted. Any such improved internal combustion engine should preferably have the injection of water and its conversion into steam controlled by a computer assembly or central processor, properly programmed in accordance with the related laws of thermodynamics and the conversion of water to steam in accordance with the xe2x80x9cSteam Tablesxe2x80x9d.
The present invention is directed towards a computer controlled internal combustion (IC) engine, and its method of operation, designed to operate on a six-stroke cycle and specifically includes the injection of water into the combustion chamber or cylinder of each of a plurality of piston and cylinder assemblies, during a predetermined portion of the six-stroke cycle. More specifically, the quantity and timing of the water injection is controlled and regulated to the extent that the injected water is prevented from turning into steam even after reaching sufficiently high temperatures because of the continuously increasing pressure within the cylinder, due to the compression of gases therein, to the extent that the water is maintained in a liquid state until the beginning of an intended xe2x80x9cauxiliaryxe2x80x9d power stroke.
More specifically, the IC engine of the present invention comprises at least one, but preferably a plurality of piston and cylinder assemblies. Each such piston and cylinder assembly includes a cylinder which serves as a combustion chamber having a piston reciprocally mounted therein, and further including intake and exhaust valves associated therewith so as to regulate the flow of fluid into an out of the cylinder. A source of ignition is also connected to each chamber and may be in the form of a spark plug, glow plug or any other applicable and/or conventional means of igniting a combustible fluid, such as a gaseous mixture of fuel and air.
In addition to the above, the improved IC engine of the present invention includes an injection assembly comprising one or more injector structures associated with each of the cylinders and disposed and structured to inject predetermined quantities of water at predetermined rates and times into the individual cylinders under the control and regulation of a central processor. A central processor or computer of the general type referred to is known in the automobile and/or internal combustion engine industry for the control and regulation of a variety of operating conditions of the IC engine. The central processor of the present invention is responsive to a plurality of sensors, all of which serve to define a sensor assembly, which sense and/or determine certain predetermined physical characteristics relating to the operation and performance of the engine.
As will be explained in greater detail hereinafter a variety of physical characteristics determined by the plurality of sensors may be used to determine the xe2x80x9cenergy contentxe2x80x9d within the cylinder during a predetermined portion of the six-stroke cycle. In turn, the energy content of a cylinder is used in determining the quantity and duration of water injection into the cylinder. Such physical characteristics may include, but are not limited to, the pressure and temperature of the interior of each cylinder at a first predetermined portion of the six-stroke cycle. The determination of the pressure and temperature may be used in the calculation of the energy content within the cylinder during a portion of the six-stroke cycle and is subject of U.S. Pat. No. 6,311,651 by the inventor hereof, which is incorporated in its entirety herein by reference.
In addition, one or more of the plurality of sensors are mounted on the engine to determine the engine speed as well as the temperature of the water being injected into the cylinder prior to its injection. The determination of the engine speed by the sensor assembly will, in turn, inform the central processor of the rate of travel of the pistons within respective ones of the cylinders. Since it is important that water, when injected into the cylinder absorb the maximum amount of heat without turning into steam, the determination of the central processor of the rate of travel of the piston within the cylinder will allow the central processor to determine the length of time a predetermined stroke exists. This in turn will allow the central processor to inject water into the cylinder at a time during a predetermined stroke that will allow the injected water to spend the maximum amount of time in the cylinder and thereby absorb the maximum amount of heat, without turning into steam. Informing the central processor of the amount of time the various quantities of injected water spend in the cylinder, absorbing heat, better assures that maximum heat energy is extracted, thereby resulting in a more efficient auxiliary power stroke being subsequently produced. The temperature of the water prior to it being injected into the cylinder will also be communicated to the central processor so as to aid in the calculation of the amount of heat required to convert the water into steam specifically during the second predetermined portion of the sixth stroke cycle.
The central processor will thereby be informed of the operating and performance characteristics of the IC engine under varying speed and load conditions. Such operating conditions will, of course, have a direct effect on the physical conditions within each of the cylinders during the operation of the IC engine. As a result the xe2x80x9cenergy contentxe2x80x9d of each cylinder, immediately prior to and during the injection of water into the cylinder will be determined at least partially by the central processor in order to determine the quantity of water to be injected into the cylinder as well as the time and duration of such injection.
More specifically, the quantity of water to be injected can be calculated based on the amount of heat required to convert it to steam. Also, the amount of water to be injected will be determined by the temperature of the water before its injection into the cylinder. It should be apparent that the higher the temperature of water being injected into the cylinder the greater the quantity of water that can be injected, in that less heat will have to be absorbed from the xe2x80x9cenergy contentxe2x80x9d of the interior of the cylinder into which the water is to be injected, to convert the injected water into steam.
Another directly related responsibility of the central processor is to calculate when or over what duration of the six-stroke cycle is the water to be injected. The timing of the water injection is important in order to prevent the water from being converted into steam during the compression stroke upon its injection into the cylinder. More specifically, as the water is injected, its temperature significantly and rapidly increases. Accordingly, the pressure exerted on the injected water must also significantly and proportionally increase in order to prevent the formation of steam.
As set forth above, the inventor herein described in detail in the above noted U.S. Pat. No. 6,311,651 that the xe2x80x9cenergy contentxe2x80x9d was capable of being determined by the on-board processor using physical parameters of the engine which included the temperature, pressure and volume of the cylinder. However, as an alternate and preferred embodiment to the invention described in the aforementioned patent, energy content or xe2x80x9cremnant energyxe2x80x9d may be determined in a different manner with minimal or no significant modification to the software of the on-board processor.
Accordingly, in the preferred embodiment of the present invention, the determination of the energy content or remant energy within a given cylinder is derived by what may be generally referred to as a xe2x80x9cdefaultxe2x80x9d determination or computation. As will be described in greater detail hereinafter, a key element in this default determination is the recognition of a predetermined value of the thermal efficiency of a particular IC engine operating under various load conditions. It is universally recognized that the thermal efficiency is the quantity of heat that is converted to motive force at the wheels of the vehicle. Further, the average thermal efficiency of an internal combustion engine is generally recognized as being generally in the range of 40%. A more precise thermal efficiency value can of course be provided, such as by the manufacturer of the engine. Accepting this 40% value for purpose of clarity, leads to the conclusion that generally 60% of the heat or energy goes to waste. In turn, the waste heat is distributed between exhaust gasses, heat detracted by the cooling system and a certain amount of loss due to friction.
Therefore, as part of the aforementioned default computation, it is understood that a predetermined amount of heat energy created by the fuel injected into a cylinder is exhausted, in a conventional four stroke cycle engine, in the fourth or exhaust stroke. As a result, the energy content can be determined, by xe2x80x9cdefaultxe2x80x9d once it is recognized that the thermal efficiency of the engine has a predetermined recognized value as well as the fact that generally half of the heat energy lost is in the gasses that are exhausted. Accordingly, the energy content during the third stroke of the six-stroke cycle engine, of the present invention, can be accurately and simply determined by xe2x80x9cdefaultxe2x80x9d, after ignition and expansion of the substantially standard fuel/air mixture.
Further, in this preferred embodiment of the present invention, the end of the third stroke represents the beginning of the second predetermined portion of the cycle of the sixth stroke cycle engine, during which the injection of water begins. This of course differs from the injection of water only during the fourth stroke, as described in detail in the above noted U.S. Pat. No. 6,311,651 by the inventor herein.
During the fourth stroke or subsequent compression stroke, the piston is rising through the cylinder so as to compress its contents, including both the combustible fluid, which had already been ignited, and the water being injected. Therefore, as the water is continuously and/or periodically being injected, in an amount based on the aforementioned xe2x80x9cenergy contentxe2x80x9d of the cylinder, during a portion or at least a majority of this compression stroke, the pressure thereon is continuously increasing. The injection of the water in a regulated and controlled manner by the central processor, as set forth above, will force the water to be maintained in a liquid state and prevent its conversion into steam until the beginning of the following power stroke. This following stroke will define an xe2x80x9cauxiliaryxe2x80x9d power stroke because of a forced travel of the piston upon the conversion of the water into steam. The result will be a gradual decrease in pressure as the piston moves towards its bottom dead center (BDC) position during this auxiliary power stroke. Therefore, subsequent to the compression of the ignited combustible fluid and the injected water, the piston will began its travel from its top dead center (TDC) position to the BDC position with the resulting gradual decrease in pressure on the injected water. Accordingly, there will be a continuous or gradual conversion of the water into steam because of the pressure reduction thereon and the fact that the water has absorbed sufficient heat from the xe2x80x9cenergy contentxe2x80x9d within the cylinder into which it is being injected to accomplish the water to steam conversion. As set forth above, this conversion will generate an auxiliary power stroke as the piston is forced to travel from its TDC position to its BDC position.
Therefore, the improved IC engine of the present invention will allow the development of significantly more power from relatively smaller size engines while operating at an increased efficiency level. The increase in efficiency will be due to the development of two power strokes using the same amount of combustible fluid or air-fuel mixture. The admission of pollutants into the atmosphere will also be reduced since the exhausting of the previously ignited combustible fluid only occurs at the end of the six-stroke cycle, along with the steam. Further, the resulting IC engine can operate on a lower compression ratio, thereby eliminating the necessity of using more expensive, high octane fuels. In addition to the above, the computer controlled IC engine of the present invention will be environmentally friendly by enabling the use of less combustible or fossil fuel, while allowing the engine to do a greater amount of work.
These and other objects, features and advantages of the present invention will become more clear when the drawings as well as the detailed description are taken into consideration.